# Chapter 24. Starting, Stopping, and Killing Processes

#### Contents:

What's in This Chapter
fork and exec
Managing Processes: Overall Concepts
Subshells
The ps Command
The Controlling Terminal
Tracking Down Processes
Why ps Prints Some Commands in Parentheses
The /proc Filesystem
What Are Signals?
Killing Foreground Jobs
Destroying Processes with kill
Printer Queue Watcher: A Restartable Daemon Shell Script
Killing All Your Processes
Killing Processes by Name?
Kill Processes Interactively
Processes Out of Control? Just STOP Them
Cleaning Up an Unkillable Process
Why You Can't Kill a Zombie
The Process Chain to Your Window
Terminal Windows Without Shells
Close a Window by Killing Its Process(es)

## 24.1. What's in This Chapter

> #### Summary Box We've already talked about so many of the topics in this chapter, here or there, that it may seem like a real hodgepodge. It's a grab-bag of important things to know about processes -- which you can think of as programs that are actually running, rather than sitting on the disk somewhere. The chapter starts out with a couple of conceptual articles. They define some important terms that you're likely to encounter in this chapter. Then we talk about the ps command, which tells you what processes you have running and just what they are up to (Section 24.5, Section 24.6, Section 24.8). The next few articles cover signals, which are one way processes communicate with one another. We cover topics like: What are signals (Section 24.10)? How to send signals from the keyboard (Section 24.11 and Section 24.12; also see Section 5.8). How shell programs can "handle" signals (Section 24.13 and Section 35.17). We go from there to a more general discussion of ways to kill processes: How to kill all your processes (Section 24.14). How to kill processes by name rather than by process ID (Section 24.16). How to stop runaway jobs (Section 24.17). Why some processes don't seem to go away when you kill them (Section 24.18, Section 24.19). How to get rid of a frozen window (Section 24.22). How to make sure processes don't die when you log out (Section 23.10). -- TOR

Copyright © 2003 O'Reilly & Associates. All rights reserved.